"The first time I heard of Mattes Schwarz, someone called him 'Stecken-Mattes'. Stecken was a defining, if almost secret, Cologne dance music venue of the 2000s and early 2010s, a minuscule basement without curfew and seemingly any other restrictions . . . While he got heavily involved in Cologne's BMX scene of the '90s, he never really stopped, and during the main years of being known as Stecken-Mattes and playing there each Friday night, he coincidently lived in Magazine Record's home base . . . I Don't Know is Mattes Schwarz's first release." --Hanna Bächer